i have a SALUS RT500RF hand held controller and a VAILLANT combi-boiler. i recently had to change the batteries in the hand held unit and since then it doesn't actually control the boiler. both red and green lights are on on the receiver unit but even if the flame is showing on the controller the heating doesn't switch on and when the heating is on and it gets too hot i try to turn it down on the HH unit but nothing happens. the boiler acts independently of the timer controls set on the HH unit too. So, does anyone have any solutions please ?